Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Extracellular invertases are suggested to play a crucial role in the arbuscular mycorrhiza (AM) symbiosis to fulfil the increased sink function of the mycorrhizal root and the supply of the obligate biotrophic AM fungus with hexoses. In tomato (Lycopersicon esculentum), LIN6 represents an apoplastic invertase which is described as a key enzyme in establishing and maintaining sink metabolism. In this study, transcript levels of LIN6 were analysed in tomato roots colonized with the AM fungus Glomus intraradices. Using real-time RT-PCR, a nearly 3-fold increase in LIN6 mRNA levels was detected at late stages of mycorrhization (11 weeks after inoculation). A 1.8-fold induction could already be achieved at earlier stages (5 weeks after inoculation) using higher inoculum concentrations, whereas wounding of non-mycorrhizal roots resulted in up to 12-fold enhanced LIN6 transcripts. As revealed by in situ hybridization, the expression of LIN6 upon mycorrhization was specifically restricted to colonized cells and to the central cylinder. Such a strongly localized pattern due to mycorrhizal cells and to the central core could also be shown for promoter activity using transgenic Nicotiana tabacum plants expressing the gene coding for beta-glucuronidase under the control of the LIN6 promoter. The moderate induction of LIN6 expression in mycorrhizal tomato roots compared with stress-stimulated induction suggested a fine-tuning in the activation of sink metabolism in the mutualistic interaction, avoiding stress-induced defence reactions.
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PMID:Arbuscular mycorrhiza induces gene expression of the apoplastic invertase LIN6 in tomato (Lycopersicon esculentum) roots. 1705 Jun 39

A 1,993 bp region upstream of the gene encoding the betaine aldehyde dehydrogenase (BADH) was isolated from Suaeda liaotungensis K., and the analysis of the promoter sequence has revealed the existence of several putative cis-elements by the PLACE database. In this study, according to the characteristic of the BADH promoter, five chimeric constructs varied in the length of promoter fragments from -1,993, -1,466, -1,084, -573 and -300 to +62 bp relative to the transcriptional start site were placed to the upstream of the beta-glucuronidase (GUS) coding region and transferred to Nicotiana tabacum L.cv.89 by Agrobacterium tumefaciens-mediated leaf-disc transformation. The functional properties of each promoter fragment were examined by GUS histochemical staining and fluorescence quantitative analyses in the transgenic tobacco leaves treated with different NaCl concentrations for 48 h. The results show that healthy transgenic plants had decreased GUS activity in leaves, whereas a higher GUS activity was observed when the transgenic plants were challenged with sodium chloride (NaCl). Induction levels were proportional to the concentration of NaCl treatment, allowing fine-tuning of protein expression. GUS enzyme activity was enhanced 6.3-fold in transgenic tobacco leaves containing -300 bp promoter fragment in the presence of 400 mmol/l NaCl compared to the noninductive leaves. This suggests that the smallest promoter fragment (-300 to +62 bp) possesses all the essential cis-acting elements and is sufficient for NaCl induction.
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PMID:Functional analysis of BADH gene promoter from Suaeda liaotungensis K. 1792 16

ATP-binding cassette transporters of the pleiotropic drug resistance (PDR) subfamily are composed of five clusters. We have cloned a gene, NpPDR2, belonging to the still uncharacterized cluster IV from Nicotiana plumbaginifolia. NpPDR2 transcripts were found in the roots and mature flowers. In the latter, NpPDR2 expression was restricted to the style and only after pollination. A 1.5-kb genomic sequence containing the putative NpPDR2 transcription promoter was fused to the beta-glucuronidase reporter gene. The GUS expression pattern confirmed the RT-PCR results that NpPDR2 was expressed in roots and the flower style and showed that it was localized around the conductive tissues. Unlike other PDR genes, NpPDR2 expression was not induced in leaf tissues by none of the hormones typically involved in biotic and abiotic stress response. Moreover, unlike NpPDR1 known to be involved in biotic stress response, NpPDR2 expression was not induced in the style upon Botrytis cinerea infection. In N. plumbaginifolia plants in which NpPDR2 expression was prevented by RNA interference, no unusual phenotype was observed, including at the flowering stage, which suggests that NpPDR2 is not essential in the reproductive process under the tested conditions.
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PMID:Identification of a cluster IV pleiotropic drug resistance transporter gene expressed in the style of Nicotiana plumbaginifolia. 1803 27

A 1.8 kb 5'-flanking region of the large subunit of ADP-glucose pyrophosphorylase, isolated from watermelon (Citrullus vulgaris S.), has fruit-specific promoter activity in transgenic tomato plants. Two negative regulatory regions, from -986 to -959 and from -472 to -424, were identified in this promoter region by fine deletion analyses. Removal of both regions led to constitutive expression in epidermal cells. Gain-of-function experiments showed that these two regions were sufficient to inhibit RFP (red fluorescent protein) expression in transformed epidermal cells when fused to the cauliflower mosaic virus (CaMV) 35S minimal promoter. Gel mobility shift experiments demonstrated the presence of leaf nuclear factors that interact with these two elements. A TCCAAAA motif was identified in these two regions, as well as one in the reverse orientation, which was confirmed to be a novel specific cis-element. A quantitative beta-glucuronidase (GUS) activity assay of stable transgenic tomato plants showed that the activities of chimeric promoters harbouring only one of the two cis-elements, or both, were approximately 10-fold higher in fruits than in leaves. These data confirm that the TCCAAAA motif functions as a fruit-specific element by inhibiting gene expression in leaves.
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PMID:Two negative cis-regulatory regions involved in fruit-specific promoter activity from watermelon (Citrullus vulgaris S.). 1907 62

We have previously isolated a Brassica juncea cDNA encoding a novel chitinase BjCHI1 with two chitin-binding domains (Zhao and Chye in Plant Mol Biol 40:1009-1018, 1999). The expression of BjCHI1 was highly inducible by methyl jasmonate (MeJA) treatment, wounding, caterpillar feeding, and pathogenic fungal infection. These observations suggest that the promoter of BjCHI1 gene might contain specific cis-acting elements for stress responses. Here, we report the cloning and characterization of the BjCHI1 promoter. A 1,098 bp BjCHI1 genomic DNA fragment upstream of the ATG start codon was isolated by PCR walking and various constructs were made by fusing the BjCHI1 promoter or its derivatives to beta-glucuronidase reporter gene. The transgenic Arabidopsis plants showed that the BjCHI1 promoter responded to wounding and MeJA treatment, and to treatments with either NaCl or polyethyleneglycol (PEG 6000), indicating that the BjCHI1 promoter responses to both biotic and abiotic stresses. A transient gene expression system of Nicotiana benthamiana leaves was adopted for promoter deletion analysis, and the results showed that a 76 bp region from -695 to -620 in the BjCHI1 promoter was necessary for MeJA-responsive expression. Furthermore, removal of a conserved T/G-box (AACGTG) at -353 to -348 of the promoter greatly reduced the induction by MeJA. This is the first T/G-box element identified in a chitinase gene promoter. Gain-of-function analysis demonstrated that the cis-acting element present in the 76 bp region requires coupling with the T/G-box to confer full magnitude of BjCHI1 induction by MeJA.
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PMID:Molecular cloning and characterization of the promoter for the multiple stress-inducible gene BjCHI1 from Brassica juncea. 1927 2

A 1,482-bp promoter sequence of the cotton cellulose synthase gene (GhCesA4) was isolated from Chinese cultivar CRI12 of Gossypium hirsutum, and transcriptionally fused to a beta-glucuronidase (GUS) reporter gene for investigation of important regions controlling gene expression in transgenic tobacco plants. Histochemical staining showed that the full-length promoter directs efficient expression of the reporter gene in the roots, hypocotyls, vascular tissues of stems, trichomes, the central leaf veins, as well as in the anthers and pollen. Quantitative measurements of GUS activity demonstrated that higher expression levels were detected in the stems, fully expanded leaves, and styles of flowers. A series of 5' progressive deletions of the promoter revealed the presence of a negative regulatory region (-767 to -424) for promoter activity and a 247-bp fragment (-247 to -1) with the vascular tissue specificity of the basic transcription activity in the GhCesA4 promoter. Exposure of the transgenic tobacco to various abiotic stresses showed that the full-length construct predominantly responded to NAA, kinetin, and sugar. Furthermore, the NAA-response region was found to be located in the -1,482/-1204 fragment, while the element(s) for the sucrose-responsive expression may be present in the -247/-1 region in the GhCesA4 promoter. These findings will not only contribute to an explanation of the molecular mechanisms by which GhCesA4 participates in secondary cell wall morphogenesis and stress responses, but will also provide a good candidate for expression or accumulation of foreign genes of interest whose products are preferentially required in vascular tissues and are inducible under auxin treatment.
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PMID:Functional analysis of a cotton cellulose synthase A4 gene promoter in transgenic tobacco plants. 1965 47


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